New 3-phenyl-1-(2-furyl)propenones, 1 and 3-phenyl-1-(2-furyl)-3-thiophenyl-propanone, 2 derivatives were synthesized, and their fungicidal activities in vitro against Botrytis cineria (BC), Valsa ceratosperma (VC), Scelerotium cepivorum (SC) and Phytophthora capsici (PC) were investigated using a generalized structure-activity relationship (SAR). The activity of 1 was superior to those of 2, and nonsubstituent, 1a and chloro group substituent, 1d of E (Syn) conformer were the most effective (EC_(50)=10∼12 ppm) compound to BC. Antifungal activities were able to predict to depend essentially on the β carbon and their positive charge from the results that the good correlation (r²= 0.90) was observed between hydrolysis rate constant (logk) of 1 and the electronic parameter (σ) of X-substituent on the β-phenyl ring.